JPS636962A - Original reading method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a document reading method that uses a line sensor to read a document as dot pattern data having a specified reading dot density.

[Prior Art] A document reading device has been developed that reads a document as dot pattern data by scanning a document in the horizontal direction at a predetermined speed with a line sensor in which a plurality of reading elements each consisting of, for example, a light receiving element are arranged in a vertical line. Such document reading devices are generally facsimile devices.

Built into copy devices, image readers, etc. and,
The dot pattern data corresponding to the document read by this document reading device is subjected to predetermined processing in the next stage dot pattern processing device. The density of read dots in the vertical and horizontal directions (scanning direction) in this document reading device has certain limitations depending on the specifications of the dot pattern processing device. That is, information cannot be processed accurately with dot pattern data having an extremely low read dot density. Furthermore, dot pattern data with an extremely high read dot density reduces the processing efficiency of the dot pattern processing device.

Note that the reading dot density changes depending on the number of reading elements arranged on the line sensor per unit distance, the reading sampling period during the scanning period of the line sensor, or the scanning speed. That is, in order to increase the reading dot density X (dat/mm) in the vertical direction, it is necessary to shorten the installation interval of the reading elements of the line sensor, or to enlarge the original using a lens or the like and input it to the line sensor. Bye.

- side, lateral direction reading dot density Y (dat / 11
1111), the sampling period may be shortened or the scanning speed may be increased.

[Problems to be Solved by the Invention] However, even with the document reading method as described above, there are the following problems. That is, if the character lines on the original are unclear or thin, when the original is read at a specified reading dot density, the thin lines will be between the dots and will not be output as dot pattern data.

Therefore, in a facsimile machine, for example, thin lines that existed in the original document may be removed from the document sent to the destination, causing a problem in which information is not accurately transmitted.

In order to eliminate this inconvenience, it is possible to increase the read dot density as described above, but if the read dot density is significantly increased above the specified dot density, the processing in the next stage dot pattern processing device becomes complicated, as described above. The problem arises that the processing time increases, and the required storage capacity also increases.

The present invention was made based on these circumstances,
The purpose of this is to first increase the reading dot density and read the original, and then set the respective logical sum values of adjacent dot data as dot data with a specified reading dot density. An object of the present invention is to provide a document reading method that can accurately read a document at a specified reading dot density even if the document is read at a specified reading dot density.

[Means for Solving the Problems] In the document reading method of the present invention, reading is performed in the vertical direction perpendicular to the scanning direction of the line sensor at a reading dot density that is a predetermined multiple of the specified reading dot density, and Divide the dot data in each column in the vertical direction of a predetermined multiple read by each reading element into unit dot data groups of a predetermined multiple, and calculate the logical sum value of all dot data constituting each unit dot data group. However, the calculated OR value of each unit dot data group is used as dot data for each column of dot pattern data of a specified reading dot density.

Further, in another invention, in addition to the above invention, reading is performed at a reading dot density that is a predetermined multiple of a prescribed reading dot density in both the vertical direction and the scanning direction of the line sensor, and the line sensor reads the dots as many as the predetermined multiple. Each time a scan is performed, a logical sum value is further calculated for each logical sum value for a predetermined multiple in the scanning direction obtained in each scan, and this logical sum value is used to calculate each column of dot pattern data with a specified reading dot density. It is used as dot data.

[Operation] With the document reading method configured in this way, the reading dot density in the vertical direction of the line sensor is set to a predetermined multiple of the specified reading dot density. The number of dot data is a predetermined multiple of the number of dot data at the specified dot density. Therefore, the number of unit dot data groups is the number of dot data in the vertical direction at the specified dot density. Each logical sum value becomes H level when there is one H level dot data in the corresponding unit dot data group. As a result, the dot pattern data formed by each logical sum value calculated from each unit dot data group includes H level dot data detected in the smallest dot unit. therefore,
The horizontal thin lines of the original are read.

Further, in another invention, the above-described logical sum calculation process is executed not only in the vertical direction of the line sensor but also in the scanning direction. That is, when the line sensor is scanned by a predetermined multiple, a logical sum value of the respective logical sum values of the predetermined multiple obtained in each scan is further calculated. Therefore, the number of logical sum values becomes the number of dot data in the scanning direction at the prescribed read dot density. - As a result, thin lines in both the vertical and horizontal directions of the document are read.

[Example] An embodiment of the present invention will be described below with reference to the drawings.

FIG. 2 is a schematic diagram for explaining the document reading method of the embodiment. That is, the reflected light from the character image drawn on the original 1 forms an image on the light receiving surface of the line sensor 3 by the lens 2.

As shown in FIG. 3, this line sensor 3 has N light receiving elements 4 as reading elements arranged at minute intervals in the vertical direction of its light receiving surface. Dot data output from each of the N light receiving elements 4 arranged in a line in the vertical direction (X direction) of the line sensor 3 is temporarily stored in the register 5.

This register 5 stores, for example, two dots when the line sensor 3 scans the original l in the horizontal direction (y direction), that is, two rows of dot data (2N It has the capacity to store each logical OR.

Connected to the register 5 are a microprocessor 7 that executes data processing via a pass line 6, and a transmission buffer 8 that temporarily stores dot pattern data converted to a specified reading dot density to be transmitted to an external dot pattern processing device. There is.

When the line sensor 3 scans in the horizontal direction (y direction), the reading dot density on the document 1 is set to a reading dot density 2 which is twice the specified reading dot density Y (dot/mm).
Let it be Y (dat/mm). That is, the scanning speed or sampling period is adjusted so that dot data is read on the original 1 at intervals of 1/2 Y (m+n).

On the other hand, in the vertical direction (X direction), the read dot density of the character image received by each light receiving element 4 arranged in the line sensor 3 is the specified read dot density X (do
The read dot density is twice that of t/mm).
/ mm), the optical system such as lens 2 is adjusted.

In this way, in this embodiment, the original 1 is read with a reading dot density twice the specified reading dot density, that is, 1/2 Read the dot data at (a++n) intervals.

In the process of scanning the line sensor 3 from the left edge of the document 1 in the right direction (y direction) in a state where the document is read at double the normal density, the microprocessor 7 performs the operations shown in FIG. Execute the reading process according to the flowchart.

That is, when the flowchart is started, the line sensor 3 is moved at Ql to the position [1/2Y (IIlm)] corresponding to the first column of the leftmost dot, which is the scanning start point. and,
A column pointer P indicating a movement step is set to an initial value of 1. Next, in Q2, the line pointer S for specifying the dot data to be subjected to data processing among the N dot data from the light receiving element 4 of the line sensor 3 is set to an initial value 1 corresponding to the highest dot data. When the above initial processing is completed, each light receiving element 4 reads dot data D1 to DN of the character image of the document 1 currently facing the line sensor 3 in one vertical column and stores it in the register 5.

Next, among the N pieces of dot data read in Q3, the S-th dot data Ds indicated by the row pointer S and the dot data S (s+1) of the (S+1)th row adjacent below
The logical sum value D s 1 is calculated and stored in the register 5. That is, in this embodiment, the unit dot data group is composed of two dot data. Next, the row pointer S is increased by 2, and in Q4, the row pointer S after the increase is
When it is confirmed that the number of light receiving elements 4 does not exceed N, the process returns to Q3 and the logical sum value of the next row pointer and the dot data of the next row pointer is calculated.

When the row pointer Q exceeds the number N of light-receiving elements 4 installed in Q4, the calculation process of each logical sum of each dot data for one row has been completed, so the line sensor 3 is moved by one dot.

Then, in the processing from Q5 to Q6, the above-mentioned Q2 to Q
The same process as in step 4 is executed to calculate the logical sum value Ds2 between the vertically adjacent dot data.

Logical sum value D of each N/2 pieces of dot data for two columns
When sl and D s2 are determined, a new logical sum value D of the logical sums D sl and D s2 that are adjacent to each other in the horizontal direction (X direction, scanning direction) is calculated in the processing from Ql to Q8.
Calculate sO. That is, this calculated logical sum value D
sO is the logical sum value of four dot data adjacent to each other, and if even one of the dot data among them becomes H level, the logical sum value DsO becomes H level. Then, the obtained logical sum value DsO is stored in the transmission buffer 8 as one piece of dot data of the dot pattern data corresponding to the specified read dot density.

When all N logical sum values DsO are stored in the transmission buffer 8 at 'QB', the processing of the dot data of two columns and sets has been completed, so the line sensor 3 is moved by one dot. Then, in Q9, the column pointer P moves in the horizontal direction of the document 1 (
When it is confirmed that the last column pointer M indicating the end in the X direction is not exceeded, the process returns to Q2, sets the row pointer S to 1, and then starts reading each dot data D1 to DN for the next column.

When the column pointer P exceeds the final pointer M in Q9, the reading of each dot data in one horizontal row of the document 1 and the logical OR calculation process have been completed, so the dots with the specified read dot density stored in the transmission buffer 8 are Send the pattern data to the dot pattern processing device.

Furthermore, if there is still data to be read on the original 1 at QIO, the process returns to Ql and the line sensor 3 is returned to the left end scanning start position.

In the document reading method having such a configuration, it is assumed that when the document 1 is read at a reading dot density twice as high as the specified reading dot density, dot data as shown in FIG. 1(a) is obtained. When the line sensor 3 first reads the dot data 1a to 1f in the first column, the logical sum value IA of the dot data 1a and 1b, as shown in FIG.
A logical sum value IB of dot data IC and 1d, and a logical sum value IC of dot data 1e and 1f are calculated.

Next, when the line sensor 3 moves to the second row (P=2),
The dot data 2a to 2f are read, and respective logical sum values 2A, 2B, and 2C are similarly calculated. Furthermore, the same figure (c)
As shown in the figure (b), the logical sum values adjacent in the horizontal direction are IA and 2A, IB and 28 . IC and 2C) are further logically summed to obtain logical sum values IA, IB, and IC.

These logical sum values IA, IB, and IC become H level when one or more dot data among the four adjacent dot data becomes H level. Therefore, the reading accuracy for reading thin lines is doubled compared to when the document 1 is read at the specified reading dot density.

Each dot data shown in FIG. 1(c) corresponds to each dot data of the dot pattern data when the document 1 is read at a specified reading dot density. Therefore, the format of the dot pattern data sent to the dot pattern processing device matches the format of the dot pattern data read at the specified reading dot density from the beginning. As a result, the processing efficiency of the dot pattern processing device is not reduced.
No extra storage capacity is required.

In this way, the format of the dot pattern data sent out (
Only the reading accuracy of thin lines can be improved without changing the reading dot density.

In the embodiment, the document 1 is read at a reading dot density twice the specified reading dot density in both the longitudinal direction (X direction) and the groove direction (X direction). The scanning direction (horizontal direction) may be read at a specified reading dot density, and only the vertical direction may be read at twice the reading dot density. In this case, only the accuracy of reading thin lines in the horizontal direction of the document 1 increases. Note that in printed characters, vertical lines are generally drawn thick and horizontal lines are drawn thin, so that the object of the present invention can be sufficiently achieved even if only the reading accuracy of thin horizontal lines is increased.

Furthermore, in the embodiment, the document 1 is read at a reading dot density twice the specified reading dot density.
The multiple of read dot density can be arbitrarily set as necessary.

[Effects of the Invention] As explained above, according to the manuscript reading method of the present invention,
- First, the reading dot density is increased to read the document, and then each logical sum value of adjacent dot data is calculated, and each logical sum value is used as dot data of a specified reading dot density. Therefore, even if the original has thin lines, it is possible to accurately read the original with the specified reading dot density.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram for explaining the operation of a document reading method according to an embodiment of the present invention, Fig. 2 is a block diagram for realizing the embodiment, and Fig. 3 is a line sensor of the embodiment. FIG. 4 is a flowchart showing the operation of the same embodiment. DESCRIPTION OF SYMBOLS 1... Original document, 2... Lens, 3... Line sensor, 4... Light receiving element, 5... Register, 7... Microprocessor, 8... Transmission buffer. Applicant's agent Patent attorney Takehiko Suzue Figure 1 Figure 3

Claims (2)

[Claims] (1) In a document reading method in which a document is read as dot pattern data of a specified reading dot density by horizontally scanning a line sensor in which a plurality of reading elements are arranged in a vertical line, Reading is performed in the vertical direction perpendicular to the scanning direction of the line sensor at a reading dot density of multiples, and the dot data of each column in the vertical direction of the predetermined multiple read by each reading element is read by the predetermined multiple of the dot data. Divide into unit dot data groups, calculate the logical sum value of all dot data constituting each unit dot data group, and use the logical sum value of each unit dot data group to read each column of dot pattern data of the specified read dot density. A document reading method characterized in that the dot data is read as dot data. (2) In a document reading method in which a document is read as dot pattern data of a specified reading dot density by horizontally scanning a line sensor in which a plurality of reading elements are arranged in a vertical line, Reading is performed in the scanning direction of the line sensor and in the vertical direction perpendicular to the scanning direction at a reading dot density of multiples, and the dot data of each column in the vertical direction of the predetermined multiple read by each reading element is Divide into unit dot data groups of a predetermined multiple, calculate the logical sum value of all dot data constituting each unit dot data group, and each time the line sensor scans by the predetermined multiple of the number of dots, further calculate a logical sum value of the respective logical sum values for a predetermined multiple in the scanning direction obtained in , and use this logical sum value as dot data for each column of dot pattern data of the specified read dot density. Characteristic manuscript reading method.